Experimental acute Babesia caballi infections: I. Red blood cell dynamics

Hematological determinations were made on blood samples from six ponies acutely infected with two dosage levels of Babesia caballi (Group 1: divided into two subgroups of three ponies each). Similar determinations were made on blood samples from three premunized ponies given challenge inoculations (Group 2), and three equidae given uninfected red blood cells (Group 3).A trend towards decreases in RBC counts, hemoglobin concentrations, and hematocrits within one to four days after inoculation (AI) was observed in all groups. However, it was marked only in Group 1. In addition, only in Group 1 was there observed a concerted anemia occurring between Days 7 and 16.Those surviving ponies in Group 1 which developed a higher parasitemia between Days 5 and 6 AI (first parasitemia peak) developed a more severe anemia between Days 7 and 16. Ponies which developed parasitemias higher than 40 × 10³ parasitized cells/mm³ at the first parasitemia peak subsequently died.Free bilirubin in Group 1 animals increased immediately after inoculation, and repeatedly exceeded normal ranges until after Day 20 AI when the RBC counts were rising. Similar changes in free bilirubin did not occur in either Groups 2 or 3. Conjugated bilirubin levels did not exceed normal ranges in any of the experimental animals.Active erythrophagocytosis was evident in histological preparations of lymph node, spleen, liver, and lung from ponies which died. Cytosiderin pigment was present in liver parenchyma, and hematin was scattered throughout lymph nodes and spleen.     

Students’ Investigations in Temperature and Pressure

Why does a balloon deflate when it is left in a cold car; or why does one have to pump up his or her bike tires in the spring after leaving them in the garage all winter? To answer these questions, students must understand the relationships among temperature, pressure, and volume of a gas. The purpose of the Predict, Share, Observe, and Explain (PSOE) activity is for students to connect the relationships among temperature, pressure, and the amount of gas. Students have many everyday experiences with these relationships, such as pumping up a basketball, but may have never thought of air in terms of pressure and temperature.     

Characteristics of a new reovirus isolated from epizootic ulcerative syndrome infected snakehead fish.

Epizootic ulcerative syndrome (EUS) has been infecting a wide range of fishes in the South and Southeast Asia for the last 2 decades. One reovirus-like agent (snakehead reovirus, SKRV), isolated from an EUS-infected snakehead fish and investigated in the present study, is the only reovirus so far isolated from an EUS-infected fish. SKRV was characterised by the presence of a double-stranded RNA genome with icosahedral symmetry and double capsid. The virus had an average size of 71 nm, a buoyant density of 1.36 g ml(-1) in CsCl and lacked a lipid-containing envelope. Apart from the above, the presence of a segmented genome and structural proteins falling into 3 specific size classes confirmed that the virus belongs to the family Reoviridae. SKRV differed from aquareoviruses by the lack of a cytopathic effect (CPE) with syncitium formation and in the segmentation pattern of RNA genome. The resistance to pH (3.0 to 9.0) and heat treatment and inability to multiply in mammalian cell lines and haemagglutinate human 'O' red blood cells (RBCs) differentiated SKRV from the rest of the similar genera in the family Reoviridae. Serological comparison indicated the antigenic distinctness of the isolate from selected American and European aquareoviruses. SKRV grew well in SSN-1 and SSN-3 cells at 25 to 30 degrees C but not in the most common Aquareovirus susceptible coldwater fish cell line--CHSE-214.     

Stability of snakehead (Ophiocephalus striatus) rhabdovirus under different environmental conditions

Snakehead rhabdovirus stored in cell culture medium was found to be relatively temperature resistant with ≥ 99.9% reduction in infectivity only occurring after 6 months at 15°C, 6 weeks at 25°C and 10 days at 35°C. At 25°C, virus stability was greatest in the range pH 5–7. Infectivity was less well retained at pH9 and rapidly lost at pH3 and pH11. Stability was poor in serum-free media with a 99.9% reduction in infectivity occurring in less than 48 hours at 25°C in de-ionized water, tap water, balanced salt solutions and artificial seawater.     

The ingestion of bacteria in suspension by the common carp Cyprinus carpio L.

Groups of large (65 -75 g) and small (8-17 g) common carp ( Cyprinus carpio L.) fingerlings were exposed to the bacterium Chromobacterium violaceurn in order to establish whether they could detect and ingest unattached bacteria. Small fish exposed to both bacteria and to cell-free bacterial extracts showed a significant increase in opercular beat rates, thus demonstrating that they are able to detect the presence of unattached bacteria in suspension. Examination of carp gut contents showed that the proportion of small fish ingesting bacteria increased with exposure time although no significant relationship was observed among larger fish. Significant, positive correlations between numbers of viable bacteria isolated from the intestinal tracts and concentration in the environment were observed. Possible mechanisms of bacterial ingestion are discussed.     

Optimizing deconvolution techniques by the application of the Münchhausen meta algorithm.

A deconvolution applied to disturbed data often gives poor results, due to fundamental difficulties associated with ill-posed problems. Many numerical and theoretical methods have been invented to circumvent this phenomenon. Their performance varies, depending on the given problem and data. The main aim of this paper is to provide a decision rule for choosing a method for deconvolution and application of this method to the same data. We have called this meta-algorithm Münchhausen. In this paper we introduce and describe for the first time the basic principle of artificial disturbance of the data in the set-up of deconvolution. We demonstrate some interesting features of the random procedure Münchhausen, such as the non parametric set-up, robustness to disturbance of the data and last but not least good performance.     

Determination of the glucocorticoids prednisone, prednisolone, dexamethasone, and cortisol in human serum using liquid chromatography coupled to tandem mass spectrometry

Glucocorticoids are an important component of immunosuppressive therapy for solid organ transplantation. A method to quantitate prednisone, prednisolone, dexamethasone and cortisol in human serum has been developed. Analysis is performed utilizing reversed-phase liquid chromatography coupled to tandem mass spectrometry. The method was validated to a lower limit of quantitation of 5.4 ng/ml for prednisone and cortisol, and 10.7 ng/ml for dexamethasone and prednisolone, with error below 7% at the lower limits. The between-day relative standard deviations ranged 2.9-7.1%. Comparison of cortisol analysis to an established method using clinical samples yielded differences below 15% for 26 of 28 determinations.     

Quantitative evaluation of the performance of different electrical tomography devices.

Two widely used electrical tomography systems, the Sheffield Mark I and the DAS-01P, were quantitatively evaluated and compared to the newly developed Goe-MF system. The performance was quantified using a hardware phantom which closely matches the real input and transfer impedances of the human thorax and allows measurements equivalent to different states of lung inflation. Our results demonstrate that adequate averaging is necessary for noise reduction for the Mark I and especially for the DAS-01P system to get meaningful results even in visualizing maximal respiratory manoeuvres. The Goe-MF system showed a notably improved signal-to-noise ratio which allows also dynamic measurements at low levels of lung volume changes, e.g., in intensive care lung injury patients.